Letter U Firearms Glossary

Arsenal Exchange - Firearms Classifieds - Industry Directory

Underbolts

A sliding bar, running longitudinally through the watertable of a break-open side-by-side gun's action, with openings through which the lumps of the barrels pass when the gun is closed. Under spring tension, this bar moves forward when the opening control is released and its two locking surfaces engage complementary slots (bites) in the rear of the two barrel lumps. Originally operated by a hinged tab in front of the trigger guard. Now invariably operated by a cam from Scott's [toplever] spindle. Most modern side-by-side guns lock closed in this manner.

Underhammer

A type of lock in which the hammer pivots in a vertical arc, striking the nipple on the underside of the barrel. Since the nipple's flash channel goes straight into the powder at the breech end of the barrel, ignition time is very fast. For this reason, and because it gets the hammer out of the way, underhammer locks are commonly used on muzzleloading benchrest rifles which are used for target shooting, and where accuracy is the goal.

Underlug

The locking lugs on a break-action firearm that extend from the bottom of the barrels under the chamber(s) and connect into the receiver bottom.

Underwater Firearm

A firearm specially designed for use underwater.

Upset Forging

A process that increases the diameter of a workpiece by compressing its length.


14 Other Firearms Definitions You Need To Know


Soft Point

A metal jacketed bullet design in which the nose of the core of the bullet is exposed to ensure the expansion of the bullet upon impact. Often abbreviated "JSP" or "SP." They tend to expand more slowly than a Hollow Point bullet and are used where deeper penetration and expansion are needed.

Beavertail

A large piece of curved metal at the top of the grip on a pistol which protects the user's hand from getting "bitten" by the hammer or slide. It is nearly always the top part of the grip safety commonly found on many 1911-style pistols.

Feed Ramp

An inclined, polished area on a repeating firearm, just behind the chamber, that helps guide a cartridge into the chamber when pushed forward by the closing bolt or slide.

Knuckle

The curved, forward end of the bar of a break-open firearm's action, about which the mounted forend iron revolves downward. This area should be kept lightly greased to avoid galling the bearing surfaces.

Speed Loader

A device used to load magazines or revolver cylinders quicker than by hand.

DA/SA

Abbreviation for Double Action/Single Action. A type of firearm that is designed to operate in double action on the first shot, and in single action on the second and subsequent shots.

Muzzle Energy

The power of a projectile or a load of shot at the point that it exits the muzzle of a firearm, normally expressed in foot-pounds.

Hammerless

A firearm with a coil-spring-actuated firing pin, or with its hammer enclosed inside the action body; i.e.. no externally visible hammer.

Folding Stock

A long gun stock that may be doubled over for conveniently compact storage.

Shell Casing

A hollow, piece of metal (or plastic in the case of a shotgun shell) that is closed on one end except for a small hole which holds a primer. The open end holds the bullet. The hollow portion holds the powder. Together the assembled unit is called a cartridge.

Slide Catch

Sometimes also known as a slide lock, slide release or slide lever. On a semi-autmatic gun, the lever or catch that holds the slide open (after the last round is fired or when racking an empty gun). Typically they are located on the left side of the frame about mide barrel. Some of the newer semi-automatic pistols have an internal slide lock. Even though on pistols with an external slide catch, you can push down on the lever to release the slide, it should never be used in such a manner. The proper way to release the slide is to rack the slide.

Crisp Trigger

A trigger that breaks (to release the hammer) easy.

Quadrail

Sometimes spelled Quad Rail. First conceived and sold by Knights Armament Company in the mid 90s when Reed Knight saw soldiers duct taping flashlights to their handguards in news footage of Panama, the quad rail has become almost a standard item found on most military rifles. Quad rails allow easy attachment of accessories which aid tactical shooters, such as lights, infrared lasers, foregrips, sling attachment points, and secondary sighting systems. However, nowadays, any full length forearms on an AR, with or without rails may also be refered to as a Quadrail.

Jaws

The vise-like device on a flintlock hammer used to hold the flint.

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1